<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <a id="a" href="https://baidu.com">baidu</a>
  <button id="open">打开子窗口</button>

  <div id="text">ssss</div>
  <script src="./render/demo3.js"></script>
</body>
</html>